image - Swift2 recuperando imágenes de Firebase

Question

Estoy tratando de leer / mostrar una imagen de Firebase. Primero estoy codificando la imagen y luego publicando esta cadena codificada en Firebase. Esto funciona bien Cuando intento decodificar la cadena codificada de Firebase y convertirla en una imagen, obtengo una excepción de valor nulo.

Así es como guardo la imagen en Firebase

var base64String: NSString!
func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
self.dismissViewControllerAnimated(true, completion: nil)
imageToPost.image = image
var uploadImage = image as! UIImage
var imageData = UIImagePNGRepresentation(uploadImage)!
self.base64String = imageData.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
let ref = Firebase(url: "https://XXX.firebaseio.com")
var quoteString = ["string": self.base64String]
var usersRef = ref.childByAppendingPath("goalImages")
var users = ["image": quoteString]
usersRef.setValue(users)
displayAlert("Image Posted", message: "Your image has been successfully posted!")
}

Así es como estoy tratando de leer la imagen de Firebase

// ViewController.swift
import UIKit
import Firebase
class ViewController: UIViewController {
@IBOutlet weak var image: UIImageView!
var base64String: NSString!
@IBAction func buttonClicked(sender: AnyObject) {
sender.setTitle("/(sender.tag)", forState: UIControlState.Normal)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let ref = Firebase(url: "https://XXX.firebaseio.com/goalImages/image/string")
ref.observeEventType(.Value, withBlock: { snapshot in
self.base64String = snapshot.value as! NSString
let decodedData = NSData(base64EncodedString: self.base64String as String, options: NSDataBase64DecodingOptions())
//Next line is giving the error
var decodedImage = UIImage(data: decodedData!)
self.image.image = decodedImage
}, withCancelBlock: { error in
print(error.description)
})
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

El error dice: "error fatal: inesperadamente encontrado nulo al desenvolver un valor opcional"; decodedData es nulo. ¿Alguien podría explicar qué está yendo mal?

Answer 1

En vez de

let decodedData = NSData(base64EncodedString: self.base64String as String,
options: NSDataBase64DecodingOptions())

intente agregar IgnoreUnknownCharacters

NSDataBase64DecodingOptions.IgnoreUnknownCharacters

Ejemplo de uso: codificar un jpg, almacenar y leer desde firebase

codificar y escribir nuestra nave estelar favorita

 if let image = NSImage(named:"Enterprise.jpeg") {
let imageData = image.TIFFRepresentation
let base64String = imageData!.base64EncodedStringWithOptions(.Encoding64CharacterLineLength)
let imageRef = myRootRef.childByAppendingPath("image_path")
imageRef.setValue(base64String)

leer y decodificar

 imageRef.observeEventType(.Value, withBlock: { snapshot in
let base64EncodedString = snapshot.value
let imageData = NSData(base64EncodedString: base64EncodedString as! String,
options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters)
let decodedImage = NSImage(data:imageData!)
self.myImageView.image = decodedImage
}, withCancelBlock: { error in
print(error.description)
})

EDITAR 2019_05_17

Actualización a Swift 5 y Firebase 6

func writeImage() {
if let image = NSImage(named:"Enterprise.jpg") {
let imageData = image.tiffRepresentation
if let base64String = imageData?.base64EncodedString() {
let imageRef = self.ref.child("image_path")
imageRef.setValue(base64String)
}
}
}
func readImage() {
let imageRef = self.ref.child("image_path")
imageRef.observeSingleEvent(of: .value, with: { snapshot in
let base64EncodedString = snapshot.value as! String
let imageData = Data(base64Encoded: base64EncodedString, options: Data.Base64DecodingOptions.ignoreUnknownCharacters)!
let decodedImage = NSImage(data: imageData)
self.myImageView.image = decodedImage
})
}

Answer 2

Ingeniero de Firebase aquí:

Recomiendo usar la nueva API de Firebase Storage para subir imágenes a Firebase. Es fácil de usar, de bajo costo y está respaldado por Google Cloud Storage a gran escala.

Puede cargar desde NSData o un NSURL apunta a un archivo local (mostraré NSData , pero el principio es el mismo):

// Data in memory
let data: NSData = ...
// Create a reference to the file you want to upload
let riversRef = storageRef.child("images/rivers.jpg")
// Upload the file to the path "images/rivers.jpg"
let uploadTask = riversRef.putData(data, metadata: nil) { metadata, error in
if (error != nil) {
// Uh-oh, an error occurred!
} else {
// Metadata contains file metadata such as size, content-type, and download URL.
let downloadURL = metadata!.downloadURL
// This can be stored in the Firebase Realtime Database
// It can also be used by image loading libraries like SDWebImage
}
}

Incluso puede pausar y reanudar las cargas, y puede monitorear fácilmente las cargas para ver el progreso:

// Upload data
let uploadTask = storageRef.putData(...)
// Add a progress observer to an upload task
uploadTask.observeStatus(.Progress) { snapshot in
// Upload reported progress
if let progress = snapshot.progress {
let percentComplete = 100.0 * Double(progress.completedUnitCount) / Double(progress.totalUnitCount)
}
}